The document discusses acceleration through examples of a Ferrari and fighter jet increasing speed from rest. It defines acceleration as the rate of change of speed over time, with units of meters/second^2. The Ferrari accelerated from 0 to 60 mph in 3.5 seconds, achieving an acceleration of 8.6 m/s^2, while the fighter jet accelerated from 0 to 200 mph in 2.5 seconds, achieving an acceleration of 40 m/s^2.

1. What's it all about? Acceleration!

2. Sports car (Ferrari F50)

3. What Happened? 0 – 60 miles per hour in about 3.5 seconds – a very fast modified sportscar!!

4. F18 Fighter Jet

5. What Happened?? A fighter on a catapult launch from an aircraft carrier. 0 – 200 mph in 2.5 seconds!!!!

6. So What? In each of the two examples the vehicle was increasing speed. It is this change in speed that we call acceleration! Acceleration is all to do with how quickly we change our speed.

7. Lets look at the Ferrari It changed speed from 0 to 60 mph, that’s about 0 to 30 meters per second (m/s). It took about 3.5 seconds for it to change its speed. So, what's the acceleration???

8. Equations We said that acceleration was how quickly we changed speed – so it is our rate of change of speed . Acceleration = Change in Speed Time taken

9. Units!! From the previous equation we can see that the formula is speed over time. We use m/s for speed and s for time. So that gives meters / second / second . This can be simply written as m/s 2

10. Back to the Ferrari then… Speed change = 30m/s Time = 3.5 s Acceleration = 30/3.5 = 8.6 m/s 2

11. Fighter Jet Speed change = 100 m/s Time Taken = 2.5 seconds. Acceleration = 100/2.5 = 40 m/s 2 A very rapid acceleration indeed!!!

12. Acceleration

13. Worked Example An aircraft is taking off. It increases its speed from 0 meters per second at the start of the runway to 55 meters per second as it is just about to take off. It takes the aeroplane 10 seconds get from 0 – 55 meters per second. What is the acceleration of the aeroplane? Speed Change = Final Speed – Start Speed 55 m/s - 0 m/s = 55m/s Acceleration = Speed Change = 55 = 5.5 m/s 2 Time Taken 10

14. So……. Acceleration SPEED CHANGE OVER TIME TAKEN